In the study, 366 patients at 22 academic centers in the U.S. were randomly assigned to receive one of the two antidepressants or a placebo for 26 weeks, in addition to their mood stabilizers. Patients also received psychological and social therapy.
The study, designed to mimic real-world conditions, differed from a typical clinical trial in that many patients had complicating disorders, including anxiety, substance abuse or psychosis.
Of the 179 participants who received an antidepressant in addition to a mood stabilizer, 23.5% achieved a durable recovery, defined as an eight-week period marked by no more than two depressive or two manic symptoms.
In the placebo group, 27.3% of patients achieved a durable recovery.
The difference between the groups was not statistically significant, researchers said.
The criteria of durable recovery were stricter than in other trials, which used rating systems to measure overall improvements in patients' moods.
Researchers reported there was no sign that Wellbutrin or Paxil could trigger a manic episode. They said 10.1% of patients on antidepressants and 10.7% of those on placebo exhibited manic symptoms.
Lead author Dr. Gary Sachs, director of the bipolar clinic at Massachusetts General Hospital, said the study should guide the way new patients were treated, but there was no need for patients doing well on antidepressants to quit taking them.
"There is no benefit from standard antidepressant medication," he said. "But there is no risk to adding it, either."
In an editorial accompanying the report, Dr. Robert H. Belmaker of Ben Gurion University in Beersheba, Israel, said the study would not settle debates about the safety and efficacy of antidepressants in treatment of bipolar disorder.
Patients who had become manic in response to antidepressants in the past would not have enrolled in the trial, he said, casting doubt on whether the drugs are safe for all bipolar patients.
Belmaker noted that two European reviews of published studies found antidepressants to be effective, and that in his own practice he prescribed antidepressants to patients with severe depression but mild mania.
He said that bipolar disorder showed wide variability in symptoms, which argued for flexibility in treatment.
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denise.gellene@latimes.com
